Moving stairway



Feb. 23, 1937. E. M. BOUTON ET AL 2,071,313

' MOVING STAIRWAY Filed Jan. 11, 1935 INVENTORS WITNESSES:

E cigar M. Baufon a? BMW/M Patented Feb. 23, 1337 PNEENT OFFICE MOVING.STAIRWAY" Edgar M. Bouton, Chicago, Ill., and GeorgeC.

Saltzman, Edgewood,

Pa assignors to West'- inghouse Electric Elevator Company; Chicago,111., a corporation of Illinois Application January 11, 1935,'Serial No.1,282

2 Claims.

Our invention relates to moving stairways in which the steps areoperated by endless gear chainsandmore particularly to means foroperating the handrails usually associated with such stairways.

In constructing moving stairways, it is customary to provide movableflexible handrails and means for causing the handrails to travel with.the stairway steps, so that persons riding the stairway may grasp thehandrail as they ascend or descend the stairs.

One object of our invention is to provide for so operating suchhandrails that they will always travel at substantially the same speedas the steps.

Another object is to provide means for automatically indicating to theattendants in charge of moving stairways when the operating mechanismfor the handrails has reached such a 0 condition that it should receiveattention and be adjusted for better operation.

It is also an object to provide a means for first giving such attendantsa visible warning signal that the handrail needs adjustment and thengiving them an audible warning signal if the handrail is not adjusted inresponse to the first warning signal.

Other objects of the invention will be apparent from the followingdescription taken in conjunction with the accompanying drawing, in whichFigure 1 is a skeleton-like view, in side elevation, taken from theinterior of a moving stairway provided With a handrail constructed inaccordance with our invention,

Fig. 2'is an enlarged view, in side elevation, looking from the interiorof the stairway, of the means for operating the handrail included inFig. 1, and

Fig. 3 is a view in cross section of the upper steps and the handrailtightening means of a moving stairway corresponding to the line IIIIIIof Fig. 2.

Referring more particularly to the drawing, we have illustrated a movingstairway as comprising an endless series of movable steps I disposed tobe moved along tracks by a pair of gear chains 3- between an upperlanding 5 and a lower landing-6. The gear chains may be supported at thelower landing and at the upper landing by suitable sprocket wheels 1 and8. Any suitable truss or frame (not shown) may be provided forsupporting the moving steps between the upper landing and the lowerlanding. The upper sprocket wheels l may be driven in any suitable fifimanner as by a motor (not shown) connected to the shaft l0 upon whichthe wheels are mounted.

Each of the chains for operating the steps comprises a plurality ofinner links M: (Fig. 2) and outer links [2 connected by pivot pins t3. Aroller I4 is disposed upon each of the pivot pins to increase the easeof operation of the chains in passing over the sprocket wheels.

Each of the steps I (Fig. 3) comprises, a frame: l5 and a stair tread l6mounted thereon. The front end ofthe frameis provided with an axle H,the outer ends of which extend through hol low pivot pins in the chaininto position to be supported by leading rollers l8; operating'upontrack rails it! while the stepis running upon the upper side ofthestairway. The rear portion of the step frame is provided with a pairofjournals 2!, in each of which is mounted a stubshaft 2;2

for atrailing roller 23. The trailing rollers run along track rail 2!!while the step moves along the upper side of the stairway.

The track rails l9 and 20 may be welded or otherwise secured to'achannel iron 24 supported upon an upwardly projecting portion of abracket member 25. A suitable angle iron guardrail 213 may be mountedabove each of the track rails ii! in a position to prevent the leadingrollers fromleaving the tracks. With this construction, the steps willbe moved along the tracks, by reason of their front axles extendingthrough the gear chains in such manner that any movement imparted to thegear chains will be imparted to the steps. It will also be apparent thatthe gear chains and steps will be supported to a greater or less extent,while between the upper and lower terminals, by the step rollersfollowing the tracks.

A suitable channel iron 21 is also mounted upon the bracket 25., a shortdistance beneath each of the gear chains for the purpose of pre-.venting the chains from sagging or' dropping beyond a predetermineddistance.

As usual in moving stairways. a traveling handrail v30 isprovided ateach side of the steps to move with the steps and at substantially thesame speed as the steps. The handrail 3,0 at the right.- handside of thesteps is mounted upon a newel wheel 3| (Fig. 1) at the lower landing andupon a pair of newel'wheels 32 and 33. at the upper landing. Aguidestrip 34 (Fig. 2) is'provided-for supporting and guiding thehandrail'between the upper and the lower landings.

Inasmuch'as'the handrail is longand flexible, it is necessaryto providesome means for keep: ing'it under'te'nsion at all times; In the presentsystem this is accomplished looping the handrail over a reversing wheel35 and a tightener wheel 36. The reversing wheel is mounted beside thenewel wheel 32 and parallel therewith. The tightener wheel 36 isrotatably mounted upon a stub axle 3! at an angle to, and between, thenewel wheel 32 and the reversing Wheel 35. The stub axle is carried by amovable carriage 38 supported by a pair of angle irons 39. The carriageis provided with grooves in its opposite sides to receive the inneredges of the angle irons, thus permitting the carriage to slide alongthe irons. The outer sides of the angle irons 39 are welded or otherwisesecured to the flanges of a. channel iron 46 which, in turn, is mountedupon the main support (not shown) for the stairway. The movable carriage38 and its supporting angle irons 39 are mounted parallel to the upperside of the stairway so that the carriage and its tightener wheel maymove toward or away from the reversing wheel 35 in accordance with thetension on the handrail.

It is desirable to operate the handrail under a predetermined tension,therefore, the tightener wheel carriage 36 is provided with a rod 4|which extends away from the side of the carriage opposite the reversingwheel and passes freely through an aperture in a channel iron 42 whichmay be firmly affixed to the stairway frame (not shown) by welding or inany other suitable manner. The projecting end of the rod M is screwthreaded to receive a cooperating threaded nut 43.

A compression spring 44 is concentrically disposed upon the rod betweenthe outer side of the channel iron 42 and the nut 43. By adjusting thenut 43, the spring 44 may be compressed to exert a predetermined tensionupon the carriage 38 and thereby cause the tightener wheel 36 to exert acorresponding tension upon the handrail 30 by expanding the loop in thehandrail disposed over the tightener wheel and the reversing wheel.Hence, with this construction the handrail may be maintained at anydesired tension by adjusting the nut 43.

Any suitable means may be provided for causing the handrail to move atthe same speed as the movement of the steps. In the present system wehave indicated a driving chain 46 (Fig. 2) passing over a sprocket wheel41 attached to the newel wheel 33, thence over a sprocket wheel 48attached to the newel wheel 32, and thence around a sprocket wheel 49attached to the driven shaft l0. Consequently, when the shaft [6 isdriven to operate the steps, the sprocket wheel 49 is driven .to operatethe chain 46 over the driven sprocket wheels 4? and 48, thereby causingthe newel wheels 32 and 33 to rotate for the purpose of moving thehandrail in accordance with the movement of the steps.

In practice it is found that the handrails usually lengthen considerablyin use. This causes the tightener wheel to move away from the reversingwheel and it ultimately reaches a point where the spring tension on thetightener wheel decreases to a point such that the handrail slips anddoes not move in synchronism with the movement of the steps. In view ofthe fact that the attendant of the stairway does not have to adjust thetightener wheel every day, it is usually forgotten and this condition isnot discovered until it is observed that the handrail fails to move withthe steps. This occurs when the friction between the handrail and thedriven newel wheels becomes so low that the handrail slips or fails tomove at all.

In practicing our invention we prevent a situa:

tion of this kind from arising by providing a means for giving theattendant a visible warning signal when the tightener wheels should bereadjustedand an additional audible warning signal if the attendant doesnot respond to the Visible Warning means and the handrail tightenerwheel slides still further toward the limit of its movement. The visiblewarning means comprises a pair of electric lamps 50 and 5| and theaudible warning means comprises a pair of electrically operated buzzersor bells 52 and 53. The lamps and bells may. be mounted in any suitablelocation, but we prefer to mount one lamp and its associated bell in theengine or driving compartment which the attendant frequents in attendingto the driving motor, etc. The other warning lamp 5| and its associatedaudible warning means 53 are preferably located at the lower terminal ofthe stairway where they may be seen and heard by any one associated withthe operation of the building. The lamps 5i] and 5| are preferably redin color and are electrically connected in a circuit including a battery54 or other suitable source of electric energy.

A normally open switch 55 mounted in a switch box 56 (Fig. 2) isprovided for controlling the circuit. The switch box 56 is slidablydisposed on a pair of supporting rails 6| mounted on the stairway frame(not shown). The position of the switch box may be adjusted by operatinga pair of adjusting nuts 62 on a rod 63, the inner end of which isattached to the switch box and the outer end of which passes through astop member 64. This adjusting means is provided so that the warningsignal means may be set to operate at any predetermined position of thetightener wheel carriage.

The switch 55 is normally maintained in open position by a triggerhandle 51 pivotally mounted in the upper part of the switch box. Aprojecting catch 58 is firmly affixed to the front portion of thecarriage 38 in such position that when the stretching of the handrailpermits the tightener wheel and its carriage to slide beyond apredetermined distance from the reversing wheel, the catch 58 strikesthe upper portion of the trigger handle 5? and thereby permits theswitch 55, which is biased to a closed position, to close its contactmembers and thereby complete a circuit for lighting the warning signallamps 56 and 5|. The lighting of these lamps indicates to the attendantthat the adjustment of the handrail and its tightener wheel needattention. After the attendant notes the lighting of a signal lamp, hemay take the first favorable opportunity, as when the stairway is shutdown at night, to shorten the handrail or he may adjust the nut 43 toincrease the tension of the spring 44 and thereby cause the handrail tooperate as usual without stopping the stairway.

If the nut 43 is adjusted, the switch box 56 should be moved forward byadjusting the nuts 62 on the rod 63 and the trigger lever 5'! should berestored to its upright position to hold the switch 55 open. After theswitch box is moved forwardly to relocate the switch 56, the warninglamps will be lighted again when the handrail becomes so loose that itpermits the tightener carriage to move toward its outer limit to againengage the trigger 51, thereby again warning the attendant of thenecessity of adjusting the tension of the handrail. The lighting of thesignal lamps 5| and 52 will also call attention to the fact that thetightener wheel has reached its limit of travel and that the handrailmust be shortened and the mg.

tion of the carriage readjusted to secure the proper operation of thetensioning means.

If the attendant fails to respond to the signal given by the warninglamps, by adjusting the compression spring 44 by means of thecompression screw 43 or by shortening the handrail, a further stretchingof the handrail will permit the tightener wheel carriage to continue itsoutward movement to such an extent that the catch 58 will then engagethe trigger handle of a switch 66, and move it to such an extent as topermit the switch 66 to close and thereby complete a circuit forenergizing the signal bells 52 and 53. Inasmuch as the signal bells 52and 53 will be heard over the section of the building at the foot of thestairway and also by any one entering the driving motor compartment, theattendants will be constrained by the continued noise to the necessaryadjustment of the handrail or the tensioning means and prevent thehandrail leaving the newel wheels and guides on which it is mounted.

It is to be understood that when the handrail tension is adjusted andthe position of the switch box 56 is readjusted, the distance betweenthe catch 58 and the trigger 5'! represents apermissible stretch in thehandrail to a point where an adjustment must be made as soon aspracticable without stopping the stairway. The moving stairway may stillbe operated with safety to passengers until the handrail stretches to anextent to cause the trigger 65 to be engaged, thereby operating theaudible signals. At this point adjustment of the spring is imperativeand a stretch much beyond this point may cause the handrail to leave itsdriving wheels with resultant danger to the passengers. When the audiblesignal is energized, therefore, the stairway should be stopped to makethe required adjustments, but such stopping should not occur until thestairway has been cleared of passengers in order to avoid the confusionand danger of suddenly stopping it while loaded.

By the foregoing means, it will be seen that we have provided forindicating to the attendants of a stairway when the handrail should beadjusted for tension before it reaches an unworkable condition and alsofor warning the attendants when the tensioning means has closelyapproached the limit of its operation, thereby permitting repairs andadjustment to be made at convenient periods before the tensioning meansceases its operation.

It will also be seen that our improvement provides for taking care ofsuch adjustment of the handrail as may be necessary without waitinguntil the apparatus suddenly stops while the stairway is in passengercarrying operation and that it thereby avoids possible injuries whichmight occur to the passengers from such sudden stopping.

Although we have illustrated and described only one specific embodimentof our invention, it is to be understood that many changes andmodifications may be made therein without departing from the spirit andscope of the invention.

We claim as our invention:

1. In a moving stairway having a plurality of movable steps, a pluralityof newel wheels, an endless flexible handrail disposed on the newelwheels for operation in accordance with the movement of the steps, adevice for applying a predetermined tension to the handrail to maintainit in a taut condition over the newel wheels, a signal device, a circuitfor connecting the signal device to a source of electrical energy, aswitch for controlling said circuit, means responsive to a predetermineddecrease in such tension, prior to the time when the tension deviceshould be readjusted, for closing the switch to energize the signaldevice for indicating that the tensioning device requires adjustment,and means for readjusting the position of the switch afterthe tensiondevice has been adjusted whereby a further decrease in the tension willagain operate the switch to energize the signal device to indicate thatthe tension de- ,vice again needs adjustment.

2. In a moving stairway having a plurality of movable steps, a pluralityof newel wheels, an endless flexible handrail disposed on the newelwheels for operation in accordance with the operation of the steps, atightener wheel disposed in engagement with the handrail, a movablecarriage for supporting the tightener wheel, a spring for applying apredetermined tension on the tightener wheel carriage to cause thetightener wheel to effect a tensioning action against the handrail,means for adjusting the tension of the spring, a signal device, acircuit for connectng the signal device to a source of energy, a switchfor controlling the circuit, means responsive to movement of thetightener wheel carriage, prior tothe time when the tension of thespring should be readjusted, for operating the switch to energize thesignal device for giving a warning indicating that the adjustment of thespring requires attention, and means for readjusting the position of theswitch after the spring has been adjusted whereby a furtherpredetermined movement of the tightener carriage will again operate theswitch to energize the signal device to indicate that the spring againneeds adjustment.

' EDGAR M. BOUTON.

GEORGE C. SALTZMAN.

